Such a radio automatically detects available channels, then accordingly changes its transmission or reception parameters to allow more concurrent wireless communications in a given band at one location.
In response to the operator's commands, the cognitive engine is capable of configuring radio-system parameters.
Traditional regulatory structures have been built for an analog model and are not optimized for cognitive radio.
Independent studies performed in some countries confirmed that observation, and concluded that spectrum utilization depends on time and place.
Geolocation combines with a database of licensed transmitters in the area to identify available channels for use by the cognitive radio network.
Timo A. Weiss and Friedrich K. Jondral of the University of Karlsruhe proposed a spectrum pooling system, in which free bands (sensed by nodes) were immediately filled by OFDMA subbands.
Applications of spectrum-sensing cognitive radio include emergency-network and WLAN higher throughput and transmission-distance extensions.
An example of the former is choosing an appropriate sensing threshold to detect other users, while the latter is exemplified by the need to meet the rules and regulations set out for radio spectrum access in international (ITU radio regulations) and national (telecommunications law) legislation.
[31] According to Bruce Fette, "Some of the radio's other cognitive abilities include determining its location, sensing spectrum use by neighboring devices, changing frequency, adjusting output power or even altering transmission parameters and characteristics.
[41] ns-3 can be also used to emulate and experiment CR networks with the aid from commodity hardware like Atheros WiFi devices.
Realizing that CR technology has the potential to exploit the inefficiently utilized licensed bands without causing interference to incumbent users, the FCC released a Notice of Proposed Rule Making which would allow unlicensed radios to operate in the TV-broadcast bands.
The IEEE 802.22 working group, formed in November 2004, is tasked with defining the air-interface standard for wireless regional area networks (based on CR sensing) for the operation of unlicensed devices in the spectrum allocated to TV service.